Cable tensioning and releasing means



Feb. 22, 1944. l E c.. HA'rcHER 2,342,271

CABLE TENsxoNING AND RELEASING MEANS v Filed June 24, 1941 s sheets-sheet 1 & x

Feb- 22, 1944- E. c. HA'rcHr-:R

CABLE TENSIONING AND RELEASING MEANS Filed June 24, 1941 s sheets-sheet Feb. 22, 1944 E...c. H A'rcHER 2,342,271

' cABLE'g'ENgINING AND RELEASING MEANS "Filed .June `24,` 1941 s sheetsheet s Patented Feb. 22, 1944 CABLE TENSIONING AND RELEASINGv RIEANS Ernest Charles Hatcher, Northwood, England, assignor to J. Stone & Company Limited, Deptford, England, a British joint-stock company- Application June 24, 1941, Serial No. 399,537 In Great. Britain July 26, 1940 (C1. 24a-10e) 2 Claims.

This invention relates to improvements in winding and tensioning means for releasable cables and steel tapes, such as are used' for supporting and releasing bombs, torpedoes or the like on aircraft. Usually for this purpose, a twoeyed bracket is xed to an aircraft and a short cable, having one end fixed to one eye, is passed around a bomb which has been elevated against stops or chocks, the opposite end of the cable being then connected to the other eye by a releasable catch. The bomb is thus supported in a cradle or sling and when the operator releases the catch, the cable end falls and swings. away as the bomb drops. The violent swing of the cable end with the end tting attached to it is a cause of damage to the aircraft structure. One object of the invention is to avoid such damage by providing for the automatic winding in of the cable when released, and for the appropriate tensioning of the cable after its end has been drawn out from the winding means, passed around a bomb or the like, and secured to the aircraft to form a cradle. Such tensioning is important for the security of the bomb in its cradle or sling.

According to this invention, one end of the cable or the like, instead of being attached to a fixed eye as aforesaid, is attached to the barrel of a spring drum and is drawn out against the action of the spring in order to be passed around a bomb and have its other end releasably attached in the manner referred to, tensioning means being then adjustable for tightening the cradle or sling formed by the cable. The cradle or sling is advantageously formed by a number of cables of relatively small diameter each being guided into its own deep winding groove in the drum so that it is wound intoa number of convolutions one outside of another. If steel tapes are used, the winding grooves need not be so deep. The outer ends of the cables 0r tapes are attached to a common yoke device adapted for being releasably connected with the eye bracket on the aircraft, such attachment advantageously incorporating adjustments for taking up slack in any cable or tape. In order to enable the tensioning means to be operative upon the cradle or sling, the drawing out of the cable from the spring drum is normally prevented by means of a oneway clutch or detent device which may be of the free-wheel ratchet or face clutch ratchet variety. To enable the cable to be drawn out to form the cradle or sling, means are provided for temporarily holding the detent means of the clutch out of action during such drawing outof the f.. ml

cable. Thus, when the cradle has been formed and the detent means have been released, the operation of the tensioning means becomes eiective for tightening the cradle because the cable can no longer be drawn out from the drum. The Winding and tensioning means of these improvements can be applied to aircraft without structural alterations being necessary, as a. spring drum unit with its tensioning means can beconveniently suspended from one of the eyes of the existing two-eyedbracket hereinbefore -referred to.

In order that the invention may be readily understood, reference is directed yto the accompanying drawings, in which:

.Figure 1 is an end elevation of a bomb or tor pedo supported by means in accordance with the invention,

Figure 2 is a longitudinal. section to a larger scale of the spring drum device 5 seen in Figure 1.

Figures 3-7 are sections on the lines III- III to VII-VII respectively of Figure 2.

Figures 8 and 9 are views similar to Figure 1 vof a modication.

Figure 10 is a fragmentary longitudinal section illustrating a modication of the construction seen in Figure 2.

A bomb. or torpedo I is seen in Figure 1 supported from a two-eyed bracket 2 by means of a sling 3. One end of the sling 3 is connected to the left eye of the bracket 2 by means of a quick release catch I and the otherl end enters and is wound upon the barrel of a spring drum device 5.

'The drum device is pivotally attached to the right hand eye of the vbracket 2 Whichlatter, it

will be understood, is secured to the underside of an aircraft.

Referring to Figures 247, the spring drum device comprises a cylindrical casing 5 having housings in its end covers 6 and "I for ball bearings 8 and 9 respectively supporting an axial shaft IIJ. The casing 5 is provided with suspension eyes I I forpivotal attachment'to the bracket 2 on the aircraft. At one end, `to the left in Figure 2, the

- shaft I0 has keyed to it .a worm wheel I2, the

I2, I3 is reduced and has keyed to it a steel collar I 8 formed with a recess I9 (Figure 4) for anchoring one end of a ilat spiral spring 2D, the other end of this spring being anchored by a bolt 2| in a peripheral recess 22 formed in the end cover 6. The opposite end of the drum is fitted with an internally toothed annulus 23, which is iixedly secured to the drum by screws 24. Upon the inner side of the end cover 1 of the casing 5 there are mounted four pinions 25 (see Figure), which mesh with the internal teeth of the annulus 23 and also with the external teeth of a sun wheel 26 revoluble around the axial shaft I9 aforesaid. The hub of the sun wheel extends through the cover 1 and is itted with the inner race of the ball bearing 9 and, externally of the cover 1, is

enlarged to form a hollow cylindrical shell 21.

The end of the axial shaft I0 within this shell 21 has keyed to it the disc element 23 of a free wheel clutch, balls or rollers 29 (Figure 7) being disposed within shaped notches 3U of the disc 28. Small spring plungers 3I constantly tend to hold the balls 29 in clutching position between inclined edges of the notches 30 and the interior of the cylindrical shell 21. The outer side of a cover 32 of this shell 21 is provided with thumb plates 33 for enabling it to be turned and the inner side is provided with ball or roller engaging studs 34 so that the balls 29 or rollers may be forced into an idle position in the depth of the notches 30 by an appropriate turning of the cover 32.

The casing 5, 6, 1 is formed with a tangential and downwardly presented thickened part 35 having vertical bores 36 (Figure 5) for the guidance of the cables 3 in their passage to and from the drum I'B. The downwardly presented face of the thickened part 35 is fitted with a layer 31 of shockprooi` material such as rubber. The cable ends passed through the vertical bores 36 aforesaid are fastened to a common yoke 38 formed with laterally extending lugs 39 for engagement with the releasable catch 4. Each cable end may be fitted with an externally screw threaded thimble 43 and the yoke 38, formed with correspondingly screw threaded holes spaced along its length, may be formed in longitudinally divided halves, the line of division passing through the centre of the holes. Each thimble 40 is appropriately disposed in a half hole in one of the divided parts oi the yoke, the other part of which is then applied and clamped to the rst by bolts III so that the thimbles 40 are tightly enclosed in the holes. The screw threading of the thimbles 43 enables the latter to be variably disposed in their holes so as to take up any degree of slackness in any one or more of the cables 3. The operation is as follows:

When a bomb I has been elevated against stops or chocks 42 Fig. 1 on the underside of the bracket 2, it is necessary to pull out the cables 3 in order to form a cradle for the bomb. This is only possible by rst turning the cover 32 of the clutch shell 21 by means of the thumb plates 33, and pressing back the balls or rollers 29 ofthe clutch or detent into the inoperative position. Thereupon the cables 3 are freely drawn out, against the action of the spring 2U, to the required length and passed under the bomb, and the yoke 38 is hooked to the releasable catch 4. The cover 32 is now released and the balls 29 are thus permitted to resume their operative position under the action of the spring plungers 3l. The hand wheel I5 is now turned to driveA the worm wheel "I3, worm wheel I2 and axial shaft I I! in the aD- propriate direction. The shaft I Il, through the free wheel clutch 29-33, drives the sun wheel 23 which drives the intermediate or planet wheels 25, and the latter drive the internally toothed annulus 23 which turns the drum I6 in the direc.A tion for applying tension to the cables 3. When the tension is suilicient and the turning of the hand wheel I5 ceases, the cables 3 cannot pull out of the drum I6 and slacken, because the drum I6 is held locked through the gearing 23, 25, 26 the free wheel clutch 253-33, the axial shaft IU and the worm gear I 2, I3 which is self-locking or irreversible in the well-known manner. The bomb I is therefore held tightly by its cradle 3 until the moment of release. Immediately the cables 3 are freed, the spring 20 revolves the drum I6 on the axial shaft I 0 and winds them in, the clutch shell 21 being meanwhile driven by the gearing 23, 25, 26 in the non-clutching or freewheeling direction. The winding in is terminated by the yoke 38 coming against the rubber facing 31 which reduces the shock.

According to a modified construction illustrated in Figure 8 a spring drum device 43 is :pivotally mounted at :44 upon a bowed arm 45 one end of which is pivotally suspended from one eye of the bracket 2.

The bowed arm 45 extends over and around the casing of the spring drum device 43 and at its opposite end is formed with a boss 46 having a screw threaded hole. A screw 41 operated by hand wheel 48 works in this boss and presses with its inner and rounded end against a seating i9- on an abutment surface formed on the `casing of the drum device 43. The spring drum device 43 may be of generally similar construction to that above described except that the worm and toothed gearing operated by the hand wheel I5 are omitted and the free wheel clutch device 29-33 is adapted to operate directly between the shaft I0 and drum I6, the shaft I IJ being non -revolubly mounted in this case.

In the operation of this construction, the cables 3 are drawn out from the spring drum device 43 against the action of a spring similar to the spring 23, after first moving the balls of the clutch or detent to the inoperative position. The cables 3 are then lapped around the bomb I to form a cradle, the yoke 38 is releasably secured to the bracket 2 and the balls of the clutch cr detent device are permitted to return to the normal and operative position. The hand wheel i3 is now operated for inward feeding of the screw 41, so that the latter rocks the drum device `43 about its pivot 44 in the direction for applying tension tothe cables 3 of the cradle. These cables cannot withdraw from the drum device 43 and slacken because the drum is now locked against reverse revolution by the clutch or detent device. Immediately the cables 3 are freed by bomb release, the spring drives the drum in the direction for winding in the cables. The pivotal mounting of the bowed arm 45 enables the drum device 43 to move towards or from the bomb I as the convolutions on the drum decrease or increase during the unwinding or winding on operations.

In the further modication illustrated in. Figure 9, the spring drum device 45 is pivotally sus'- pended by a screw 5I! working in a hand nut 5I pivotally supported in an eye of the bracket 2. The only difference between this arrangement and that shown in Figure 8 is that the hand nut 5I is revolved to pull the screw 53 andv spring drum device 45 upwards, when tension is to 'be applied to the cables 3 of the cradle.

In Figure 10 a face ratchet clutch takes the place of the ball or roller clutch 21 to 29 of Figures 2 and '7. Instead of the extended hub of the sun wheel 26 being enlarged to form a hollow cylindrical shell 21, as in Figure 2, it is here enlarged to form a disc 21a, the face of this disc being formed with radial ratchet teeth 52. A co-operative clutch part 53 is feathered on the shaft I and is normally urged into clutching engagement by a spring 54 acting between an internal shoulder of the clutch part 53 and an abutment disc 55 xed on the end of the shaft I0. A knob 56 screwed on the clutch part 53 enables the latter to be pulled out for declutching. The operation of this construction is the same as that described with reference to Figures 2 to 7 except that when the cables 3 are to be pulled out from the drum to form a cradle, the knob 56 is operated to declutch the part 53 from the disc 21a. When the cables 3 have been suiiciently withdrawn and formed into a cradle, the knob 5B is released and the spring 54 again clutches the parts 53 and 21a. Consequently the shaft l0 can now drive the drum I6 through the clutch 53, 21a and gearing 23 to 26 in the direction for applying tension to the cables. When the cables are freed for bomb-release, and the drum I6 is driven by its spring to wind in the cables, the part 21a will be driven through the gearing 23, 25, 26 in the direction in which its ratchet teeth `slip past those of the clutch part 53.

alloy casting. The said devices not only protect the structure against damage by flying cable ends and aiord secure cradling but they also facilitate expeditious loading of an aircraft with its complement of bombs.

I claim:

1. In a bomb sling device wherein the sling is composed of a. plurality of flexible elements which are windable into respective grooves of a Winding drum, the combination of a manually operable self-sustaining Worm and worm wheel gearing, a mechanical advantage gear train operative between the worm wheel of said gearing and said drum, a one-Way clutch operative for permitting one-Way operation only of said drum by said gearing and gear train, manually operable release means 'operatively connected with said clutch, and drum-driving means operative for revolving said drum and causing it to overrun said clutch for the quick winding in of said sling when unloaded.

2. In a bomb sling device wherein the sling is composed of a plurality of exible elements which are windable into respective grooves of a winding drum, the combination of a manually operable self-sustaining worm and worm wheel gearing, a mechanical advantage gear train operative between the Worm wheel of said gearing and said drum, a one-way clutch operative for permitting one-way operation only of said drum by said gearing and gear train, manually operable release means operatively connected with said clutch, and a coil spring operative for revolving said drum and causing it to overrun said clutch for the quick winding in of said sling when unloaded.

ERNEST CHARLES HATCHER. 

